The investigation and treatment of secondary anaemia.

Secondary anaemia or the anaemia of chronic disease (ACD) is the commonest form of anaemia in hospitalised patients and the second most prevalent anaemia worldwide after iron deficiency. It is characterised by defective iron incorporation in erythropoiesis, an impaired response to erythropoietin, a decrease in erythropoietin production and cytokine induced shortening of red cell survival. For many patients with ACD the cause is apparent but for many others the underlying disease needs to be determined and such patients are often referred to haematologists for investigation. The search for the cause can be a fascinating exercise in good history taking, examination skills and performing and interpreting appropriate investigations. This review covers the pathogenesis and causes of ACD and then discusses the clinical and laboratory investigation of a patient with suspected ACD. Finally, the management of a patient with ACD is discussed including erythropoiesis stimulating agents (ESAs), intravenous iron and future therapies.